1. Field of the Invention
The invention relates to a technology related to a method for measuring laser scanning velocity.
2. Description of Related Art
In recent years, a hot stamp material has been applied more widely. In a hot stamp material, an oxide film is formed on a surface of a steel plate by performing hot forming. Since an oxide film is a factor for deteriorating adhesion of paint, it is necessary to remove an oxide film on a surface. As a method for removing an oxide film formed on a surface of a hot stamp material, a surface treatment technology using pulsed laser is known. In the surface treatment technology using pulsed laser, factors for deciding processing conditions include a laser energy amount per pulse, oscillation frequency of laser, and laser scanning velocity.
Inspection equipment that is used for a processing technology using a laser includes, for example, the one described in Japanese Patent Application Publication No. 62-114786 (JP 62-114786 A) stated below, which is publicly known. The inspection equipment described in JP 62-114786 A detects sound during processing to inspect a processing state. In such equipment, since head scanning velocity and head moving velocity are the same, the laser scanning velocity is easily detected by detecting the head moving velocity.
Meanwhile, as a laser beam machining apparatus, there is one described in Japanese Patent Application Publication No. 2012-256062 (JP 2012-256062 A) stated below, having a structure in which a laser irradiation head is not displaced. In the laser beam machining apparatus disclosed in JP 2012-256062 A, since a mirror operates inside the irradiation head, laser scanning is performed without displacing the irradiation head itself.